Science · 8th Grade

Active learning ideas

Electromagnets and Their Uses

Active learning builds deep understanding of electromagnetism by letting students feel the pull of magnetic fields with their own hands. When 8th graders wrap wire, connect batteries, and lift paper clips, they see cause and effect in real time. This hands-on work makes abstract ideas—like how current creates a field—tangible and unforgettable.

• Common Core State Standards
• MS-PS2-5

• 30–55 min
• Pairs → Whole Class
• 3 activities

Activity 01

• Project-Based Learning
• 50 min · Small Groups

Lab Investigation: Building and Testing an Electromagnet

Student groups wrap varying numbers of coils of insulated wire around an iron nail and connect it to a battery. They count how many paper clips each configuration picks up, systematically varying coil number while keeping current constant, then voltage while keeping coil number constant. Groups share results on a class data table and draw conclusions about each variable.

Explain how an electric current can create a magnetic field.

Facilitation Tip

During Lab Investigation, have students record coil count, battery count, and paper clip pickup in a shared class chart so everyone sees how variables connect.

What to look for

Present students with three electromagnets, each with a different number of wire coils. Ask them to predict which will be strongest and then test them by counting how many paper clips each can pick up. Discuss why the results match their predictions.

• Apply
• Analyze
• Evaluate
• Create
• Self-Management
• Relationship Skills
• Decision-Making

Activity 02

• Project-Based Learning
• 55 min · Small Groups

Engineering Design Challenge: Electromagnet for a Purpose

Each group receives a design brief: build the strongest electromagnet possible from given materials, or build one that can be switched on and off remotely, or build one that lifts exactly 10 paper clips (not more, not fewer). Groups plan, build, test, and present their design rationale and results to the class.

Analyze the factors that affect the strength of an electromagnet.

Facilitation Tip

For the Engineering Design Challenge, set a clear weight goal (e.g., lift 50 paper clips) to focus the build and make testing consistent across teams.

What to look for

Pose the question: 'Imagine you need to build an electromagnet to sort iron ore from other rocks. What factors would you adjust to make your electromagnet as strong as possible?' Guide students to discuss coil number, current, and core material.

• Apply
• Analyze
• Evaluate
• Create
• Self-Management
• Relationship Skills
• Decision-Making

Activity 03

• Gallery Walk
• 30 min · Pairs

Gallery Walk: Electromagnet Applications

Post images and brief descriptions of six electromagnetic technologies (electric motor, MRI scanner, maglev train, electric guitar pickup, hard disk, junkyard crane). Pairs visit each station, identify which factors (coil count, current, core material) are engineered for each application, and explain why. The class shares the most interesting engineering decision from each station.

Design an electromagnet for a specific application.

Facilitation Tip

During the Gallery Walk, post application photos with brief captions so students focus on how electromagnet design matches function in real devices.

What to look for

On an index card, ask students to draw a simple diagram of an electromagnet and label the parts that affect its strength. Then, have them write one sentence explaining how increasing the current would change the electromagnet's power.

• Understand
• Apply
• Analyze
• Create
• Relationship Skills
• Social Awareness

A few notes on teaching this unit

Teachers should emphasize variable control in the lab—only change one factor at a time—so students learn scientific method alongside physics. Avoid rushing to conclusions; let failed builds (like melted wire) become teaching moments about limits of current and heat. Research shows that when students graph their data, they better grasp proportional relationships between coils and strength.

Students will connect the number of coils, battery voltage, and core material to the strength of their electromagnet. They will explain why an electromagnet can be turned on and off, and describe at least two real-world uses based on its adjustable power. Clear labeling and measured data in their lab notes will show their grasp of variables and results.

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Watch Out for These Misconceptions

• During Lab Investigation: Watch for students who treat their electromagnet like a permanent magnet and expect it to stay on or lift objects without a battery connection.

  Have students deliberately disconnect the battery to see the electromagnet turn off immediately—this concrete action shows the on/off control that permanent magnets lack.

• During Lab Investigation: Watch for teams who stack multiple batteries hoping for unlimited strength.

  Ask students to feel the wire after testing and connect heat to reduced performance—this links engineering limits to physical science in a memorable way.

• During Lab Investigation: Watch for students who assume only iron nails work as cores.

  Provide a plastic pen core and an empty coil setup so students test all three options and rank their strengths based on paper clip pickup data.

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Methods used in this brief

• Project-Based Learning
• Gallery Walk